During fetal development, germ cells in the ovaries develop into oogonia which then become primary oocytes. By birth around 1 million primordial follicles exist, each containing an immature oocyte surrounded by a single layer of cells. At puberty hormone stimulation causes a few hundred follicles to mature each month, with only one oocyte being ovulated. If fertilization does not occur, the corpus luteum regresses and menstruation begins. The female reproductive system includes ovaries, fallopian tubes, uterus, cervix, and vagina which work together to allow fertilization and implantation if pregnancy occurs.

1. THE FEMALE REPRODUCTIVE
SYSTEM
Exercise 31
A&P 233

2. FEMALE REPRODUCTION
 Unlike males, who are
able to produce sperm
cells throughout their
reproductive lives,
females produce a
finite number of egg
cells.
 During early fetal
development germ
cells migrate into the
ovaries and
differentiate into
oogonia

3. OOGONIA
 The oogonia divide by
mitosis for the next few
months and some
differentiate into
primary oocytes.
 By fifth month there are
about 7 million primary
oocytes, but most will
degenerate during the
next 2 months

4. OOGONIA
 Those that remain will be
surrounded by a single
layer of squamous
epithelial cells (follicle
cells) called a primordial
follicle.
 Degeneration of primary
oocytes continues.
 At birth =1million
primordial follicles
 At puberty 400,000
remain
 Only 400-500 will reach
maturity

5. OVARIAN CYCLE
 Monthly changes that
occur in the ovary during
a woman’s reproductive
life.
 Each month FSH
stimulates primordial
follicles to grow and
mature (follicular phase)
 Ovulation- release of the
egg (LH)
 Luteal phase the corpus
luteum produces
progesterone that
maintains uterine walls
If fertilization does not occur,
the corpus luteum degenerates,
within 2 weeks into a mass of
scar tissue called the corpus
albicans

6. GROSS ANATOMY
 The ovaries are solid,
ovoid structures, about 2
cm in length and 1 cm in
width.
 Like the testes, they
develop from embryonic
tissue along the posterior
abdominal wall, near the
kidneys.
 Accessory organs include
the uterine tubes, uterus,
and vagina.

7. 7
UTERINE TUBES
(FALLOPIAN TUBES)
 Receive the ovulated oocyte and provide a site for
fertilization
 Empty into the superolateral region of the uterus via the
isthmus
 Expand distally around the ovary forming the ampulla
 The ampulla ends in the funnel-shaped, ciliated
infundibulum containing fingerlike projections called
fimbriae

8. 8
UTERINE TUBES
(FALLOPIAN TUBES)
 Function: events occurring in the uterine tube
 Fimbriae sweep oocyte into tube, cilia &
peristalsis move it along, sperm reaches
oocyte in ampulla, fertilization occurs
within 24 hours after ovulation & zygote
reaches uterus about 7 days after ovulation

9. 9
FALLOPIAN TUBE HISTOLOGY
Cilia sweep egg/zygote toward
the uterus

10. 10
UTERUS
 Hollow, thick-walled organ located in the pelvis anterior to
the rectum and posterosuperior to the bladder
 Body: Major portion of the uterus
 Fundus: Rounded region superior to the entrance of the
uterine tubes
 Isthmus: Narrowed region between the body and cervix

11. 11
UTERUS

12. 12
UTERINE HISTOLOGY
 Endometrium
 Simple columnar epithelium
 Stroma of connective tissue and endometrial glands
Stratum functionalis: Shed during menstruation
Stratum basalis: Replaces stratum functionalis each
month
 Myometrium
 3 layers of smooth muscle
 Perimetrium
 Visceral peritoneum

13. 13
UTERINE
HISTOLOGY

14. 14
ENDOMETRIUM
Simple
columnar
epithelium
Endometrial glands

15. ENDOMETRIUM
 Proliferative phase: glands
and blood vessels scattered
throughout the functional
zone with little or no
branching.
 New glands form and
endometrium thickens.
 Secretory phase: glands
are enlarged and have
branches. Preparing the
endometrium for
implantation
 If no implantation then
endometrium breaks down
and menstruation begins.

16. 16
FEMALE: LATERAL VIEW

17. 17
CERVIX
 Narrow lower neck of the uterus which projects into the
vagina inferiorly
 Cervical canal – cavity of the cervix that communicates
with:
 The vagina via the external os
 The uterine body via the internal os
 Cervical glands secrete mucus that covers the external os
and blocks sperm entry except during midcycle

18. 18
Fornix
Endocervical canal

19. 19
VAGINA
 Thin-walled tube lying between the bladder and the rectum,
extending from the cervix to the exterior of the body
 Wall consists of three coats: fibroelastic adventitia, smooth
muscle muscularis, and a stratified squamous mucosa
 Mucosa near the vaginal orifice forms an incomplete
partition called the hymen
 Vaginal fornix: upper end of the vagina surrounding the
cervix

20. 20
FEMALE EXTERNAL GENITALIA
 Mons pubis: fatty pad over the pubic symphysis
 Labia majora & minora: folds of skin encircling vestibule
where find urethral and vaginal openings
 Clitoris: small mass of erectile tissue
 Bulb of vestibule: masses of erectile tissue just deep to the
labia on either side of the vaginal orifice
 Perineum: Area between the vagina and anus

21. 21
FEMALE EXTERNAL GENITALIA
Perineum

22. 22
BARTHOLIN’S GLANDS
(AKA: VESTIBULAR GLANDS)
 The Bartholin's glands are located on each side of the
vaginal opening.
 They secrete fluid that
helps lubricate the vagina.
 Sometimes the ducts of
these glands become
obstructed.
 Fluid backs up into the gland
and causes swelling
(Bartholin's cyst)

23. 23
MAMMARY GLANDS
 Modified sweat glands that produce milk (lactation)
 Amount of adipose determines size of breast
 Milk-secreting glands open by lactiferous ducts at the nipple
 Areola is pigmented area around nipple
 Suspensory ligaments suspend breast from deep fascia of
pectoral muscles (aging & Cooper’s droop)
 Mammary line is a thickened ridge of embryonic tiwwue that
extends from the axilla to the groin.

24. 24
BREAST

25. 25
BREAST
 Prolactin from the
pituitary gland
stimulates the
synthesis of milk
 Oxytocin from
the posterior
pituitary gland
stimulates milk
ejection

26. 26
LYMPHATIC
DRAINAGE
 Lymph nodes
draining the
breast are located
in the axilla.

27. OOGENESIS: BEFORE BIRTH
27
 During fetal development,
oogonia (stem cells)
divide by mitosis to make
primary oocytes
 Primary oocytes begin
meiosis and stop in
prophase I until puberty
 Primordial follicles:
Support cells that
surround the oocyte in the
ovary
 2 million present at birth
 400,000 remain at puberty

28. 28
OOGENESIS: AFTER PUBERTY
 Each month, hormones cause several follicles to
develop, which triggers the primary oocyte to resume
meiosis I
 Polar bodies: When the cell divides, all the cytoplasm
and organelles stay with one of the new cells, the other
cell is just DNA, and is called a polar body and is
discarded
 Secondary oocyte: The stage at which ovulation occurs.

29. 29
OOGENESIS: AFTER PUBERTY
 The secondary oocyte begins meiosis II, but stops in metaphase
II
 The secondary oocyte is ovulated
 Meiosis II is completed only if it is fertilized.

30. 30
OOGENESIS

31. 31
LIFE HISTORY OF OOGONIA
 As a fetus, oogonia divide to produce millions by mitosis
but most degenerate (atresia)
 Some develop into primary oocytes & stop in prophase
stage of meiosis I
 200,000 to 2 million present at birth
 40,000 remain at puberty but only 400 mature during a
woman’s life
 Each month, hormones cause meiosis I to resume in
several follicles so that meiosis II is reached by ovulation
 Penetration by the sperm causes the final stages of
meiosis to occur

32. 32
OVARIES
 Each follicle consists of an immature egg called an oocyte
 Cells around the oocyte are called:
 Follicle cells (one cell layer thick)
 Stimulated to mature by FSH from the pituitary gland
 Granulosa cells (when more than one layer is present)
 Thecal cells: Cells in the ovarian stroma
 Thecal & granulosa cells work together to produce estrogen
 A protective layer of glycoprotein forms around the egg
called the zona pellucida

33. 33
FOLLICLE DEVELOPMENT
1. Primordial follicle: one layer of squamous-like
follicle cells surrounds the oocyte
2. Primary follicle: two or more layers of cuboidal
granulosa cells enclose the oocyte
3. Secondary follicle: has a fluid-filled space
between granulosa cells that coalesces to form a
central antrum
4. Graafian follicle: secondary follicle at its most
mature stage that bulges from the surface of the
ovary
5. Corpus luteum : ruptured follicle after ovulation

34. 34
OVARY HISTOLOGY

35. 35
OVARY HISTOLOGY

36. 36
Zona pellucida
1° Oocyte
(arrested in prophase I)
Granulosa cells
Thecal cells
Nucleus
Primordial
follicle
Primary Follicle

37. 37
SECONDARY FOLLICLE
Fluid-filled antrum

38. 38
GRAAFIAN FOLLICLE
Fluid filled antrum
Granulosa cells
Oocyte 2°
Corona radiata
Stalk
Zona pellucida

39. CORPUS LUTEUM
 After ovulation, the
remains of the follicle
are transformed into a
structure called the
corpus luteum.
 If a pregnancy occurs,
it produces
progesterone to
maintain the wall of the
uterus during the early
period of development.

40. CORPUS ALBICANS
 If fertilization does not
occur, the corpus
luteum will begin to
break down about 2
weeks after ovulation.
 Degeneration occurs
when fibroblasts enter
the corpus luteum and
a clump of scar tissue
forms called the
corpus albicans.

41. OVARIAN AND UTERINE CYCLES

42. TODAY’S ACTIVITIES
 View female reproductive organs on the models
 View slides of ovaries, fallopian tubes, uterus-
proliferative, secretive, menstrual